$var ??= 1;
$var[] .= 'stringgg';
$var[1] |= 1;
$var['key'] ^= 1;
$var[$var['key']] &= 1;
$var[$var['key']][] <<= 1;
$var[][$var['key']] >>= 1;

list($var, $bar) += tuple(1, 1);
list($var[], $bar) -= tuple(1, 1);
list($var[1], $bar[]) *= tuple(1, 1);
list($var['key'], $bar[1]) /= tuple(1, 1);
list($var[$var['key']], $bar['key']) %= tuple(1, 1);
list($var[$var['key']][], $var[$var['key']],) **= tuple(1, 1);
